Nerve stimulation reduces pain and opioid use after orthopedic surgery

The study enrolled 65 patients undergoing common outpatient joint surgery, such as bunion surgery in the foot or rotator cuff repair in the shoulder. All patients underwent lead placement near the nerve(s) serving the surgical joint. Half of the patients were randomly assigned to active electrical stimulation, adjusted to achieve the desired sensory change - sometimes described as feeling like a "pleasant massage." The remaining patients received an inactive "sham" treatment, with a pulse generator that appeared to function normally, but did not deliver any electrical current. After one week, pain scores and opioid use were compared between groups. Evaluations were performed in "double-masked" fashion: neither the researchers nor the patients knew which treatment the patient was receiving.

The results showed significantly lower pain ratings in the active nerve stimulation group. Mean pain score (on a 0 to 10 scale) was 1.1 in patients receiving active treatment, compared to 3.1 in the sham group.

Active nerve stimulation was also associated with a much lower use of opioids to control postoperative pain. Median opioid dose (oral morphine equivalents) for the entire first week after surgery was 5 milligrams in the active treatment group, compared to 48 milligrams in the sham group. That's an important benefit due to the possible adverse effects of postoperative opioids, such as nausea, constipation, sedation, and respiratory depression.

Although the trial was designed as a pilot study, the results "stand on their own and indicate that percutaneous peripheral nerve stimulation is highly effective for acute pain," Dr. Ilfeld and coauthors wrote. They outlined plans for a subsequent study that is currently enrolling a far larger number of patients and will include a more complete assessment of the treatment effect across patient subgroups.